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Date Permissions Signed

5-22-2018

Date of Award

Winter 1987

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Geology

First Advisor

Wodzicki, Antoni

Second Advisor

Babcock, R. Scott (Randall Scott)

Third Advisor

Burmester, Russell F.

Abstract

The Bowers Supergroup of northern Victoria Land, Antarctica is at least 6.5 km thick and consists of Solidarity, Molar, and Glasgow Formations of the Middle Cambrian Sledgers Group; Middle to late Cambrian Mariner Group; and Middle Ordovician Leap Year Group. The Solidarity Formation is at least 0.4 km thick and consists of submarine tholeiites. The Molar Formation is up to 2.7 km thick and consists of slope-facies turbidites in its southwesternmost extent and shelf-facies sediments in its northeasternmost extent. Sediment provenance was the Glasgow Formation and a continental landmass lying northeast of the southwestern sloping Bowers basin. The Glasgow Formation is up to 2.7 km thick and consists of tholeiitic and calc-alkaline basalts to rhyolites erupted along a magmatic arc probably related to eastward subduction. The Mariner Group is a regressive marine sequence deposited during tectonic quiescence. The Leap Year Group rests unconformably on the Mariner and Sledgers Groups and consists of up to 2.5 km of molasse derived in part from the Granite Harbour Intrusives. The Bowers Supergroup was folded about N30ºW axes, metamorphosed to the prehnite-pumpellyite facies, then tectonically juxtaposed by strike slip faults between the Wilson and Robertson Bay terranes.

Deposition of the Leap Year Group, folding, metamorphism, and faulting occurred between 480 to 425 Ma and were the results of collision between the Wilson and Bowers terranes representing the Ross Orogeny in northern Victoria Land. Between 420 and 384 Ma, refolding about N60ºE axes, normal faulting, and the emplacement of the Admiralty Intrusives occurred during the Borchgrevink Event by which time the terranes may have become stitched. The allochthonous nature of the rocks of the Bowers Supergroup may preclude their correlation with those of the Dundas Trough in Tasmanis.

Type

Text

Keywords

Petrology, Tectonic evolution, Bowers Supergroup

Publisher

Western Washington University

OCLC Number

1047604404

Geographic Coverage

Victoria Land (Antarctica)

Genre/Form

masters theses

Language

English

Rights

Copying of this thesis in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

REDUCED - Geology of the Western Bowers Mountains - Plate 1.pdf (2010 kB)
Plate 1 - Geology of the Western Bowers Mountains

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